It may be desirable to retransmit data, for example, voice data, in a wireless communications system. One approach to retransmitting data may include implementing a retransmission site or system using two wireless communications devices. A two device retransmission system typically operates using multiple frequencies and multiple antennas, for example, one for receiving data and another for retransmitting the data, to avoid a collision. Co-location interference mitigation techniques are typically used in such a two device approach. In some implementations, the two wireless communications devices may be configured to operate in a back-to-back configuration.
One example, of a two device retransmission system is the Single Channel Ground and Airborne Radio System (SINCGARS). SINCGARS uses multiple wireless communications devices at a given retransmission site and operates using multiple frequencies. One frequency is for a transmitting network. One frequency is for a repeater network. One radio receives data while one radio transmits. This may be accomplished via a back-to-back cable connection.
Another approach to retransmitting data may include implementing a retransmission site or system using a single wireless communications device. Similar to the two device approach described above, a single device retransmission system operates using multiple frequencies and multiple antennas. Operator coordination is also typically required for retransmission sequences. For example, operator coordination may be desired when the retransmission is directly performed. Furthermore, in a single device system retransmission of streaming data, such as, for example, streaming audio, may not be possible, as retransmission are performed in bursts rather than a synchronous data stream.
U.S. Pat. No. 4,513,412 to Cox discloses a time division adaptive retransmission technique for portable radio telephones. More particularly, Cox discloses a portable transceiver and a remote terminal station each using at least two antennas with different polarization transmission capabilities for an adaptive retransmission technique. The terminal station transmits the same preamble signal in at least two time slots of a frame period of a time division sequence using the antenna receiving the strongest signal from the transceiver in the immediately prior frame period followed by a binary message signal using the same antenna. The transceiver receives each of the preamble transmissions from the terminal station via a separate one of differently oriented antennas and determines which antenna received the strongest signal. The message signal from the terminal station is then received via the antenna of the transceiver having received the strongest signal and also sends its response message signal on that antenna during a separate time slot of a frame period.
U.S. Pat. No. 7,031,658 to Dibernardo discloses a single radio retransmission system using a half duplex radio. More particularly, Dibernardo discloses a transmitting terminal using only a transmit segment of a frame, and a receiving terminal using only the receive segment of each frame. A retransmission terminal receives data in its receive segment and transmits the data, buffered, in its transmit segment.